[pve-devel] systemd notify/watchdog

[Alexandre DERUMIER]

>> which could be great for some services, like pvestatd. (which sometimes can 
>> freeze which slow/bad storage stats) 
>
>Unfortunately, a restart does not help in that case? 
Maybe not in that case , but I have already see a lot of time the pvestatd  hanging, and a restart was doing the job.



>>I already played around with that feature, but AFAIK it needs /dev/watchdog? Or 
>>does it 
>>work without opening /dev/watchdog? 

I think it's different than hardware watchdog (in case of system hang).

Here it's more software watchdog, services tell to systemd that they are running. 
(for pvestatd, between each loop for example)
and if systemd don't receive the notify, it's restart the service.


http://0pointer.de/blog/projects/watchdog.html


----- Mail original -----
De: "dietmar" <dietmar at proxmox.com>
À: "aderumier" <aderumier at odiso.com>, "pve-devel" <pve-devel at pve.proxmox.com>
Envoyé: Mercredi 4 Mars 2015 06:39:53
Objet: Re: [pve-devel] systemd notify/watchdog

> systemd have a watchdog feature 
> 
> http://man7.org/linux/man-pages/man3/sd_watchdog_enabled.3.html 
> 
> which could be great for some services, like pvestatd. (which sometimes can 
> freeze which slow/bad storage stats) 

Unfortunately, a restart does not help in that case? 

> The idea is that the application need to send notifify at regular interval to 
> systemd, 

I already played around with that feature, but AFAIK it needs /dev/watchdog? Or 
does it 
work without opening /dev/watchdog? 

/dev/watchdog can be used only once, and I have other plans for it (ha soft 
fence).